Q214830: BUG: Tab Control Initialization Problem with Control Array

Article: Q214830
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0,6.0
Operating System(s): 
Keyword(s): kbTabCtrl kbVBp500bug kbVBp600bug kbGrpDSVB kbDSupport
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SYMPTOMS
========

The Tab Control is not able to initialize correctly when placing controls that
are members of a control array on separate tabs from the load event of the form
on which the Tab Control was placed. All the controls are drawn on a single tab
instead of on the tabs for which they were intended. This problem occurs in
Visual Basic 6.0 and Visual Basic 5.0 with service pack 2 or later.

RESOLUTION
==========

Method 1:

To work around this problem, move the code that places controls on the tabs from
the load event to the Activate event of the form. Use a global flag to determine
if the Activate event was fired without unloading the form. For example, use the
sample project created in "Steps to Reproduce Behavior" below and follow these
steps:

1. Move the code listed in step 5 from the Load event to the Activate event of
  Form1.

2. Modify the code in the Activate event by replacing it with the following:

  Dim i as integer
  If ActivateFlag = False Then
      For i = 1 To 3
          SSTab1.Tab = i - 1
          Load Text1(i)
          Set Text1(i).Container = SSTab1
          Text1(i).Top = i * (SSTab1.TabHeight + 100)
          Text1(i).Left = i * 200
          Text1(i).Visible = True
      Next i
      ActivateFlag = True
  End If

3. From the Project menu, add a Standard Module (Module1) to the project and add
  the following line of code to Module1:

  Public ActivateFlag as Boolean

4. Place the following line of code in the Unload event of Form1:

  ActivateFlag = False

5. Run the application and note that all members of the TextBox control array
  are displayed on the correct tab.

Method 2:

Another workaround is to place the control loading code in a global procedure.
Call this procedure before calling the Show method for the form containing the
tab control. For example:

1. Follow the steps 1 through 4 in "Steps to Reproduce Behavior" below.

2. From the Project menu, add a (BAS) Module to the project and copy and paste
  the following code to General Declarations area of Module1:

  Sub MyTabSetup()
      Dim i As Integer
      With Form1
          For i = 1 To 3
              .SSTab1.Tab = i - 1
              Load .Text1(i)
              Set .Text1(i).Container = .SSTab1
              .Text1(i).Top = i * (.SSTab1.TabHeight + 100)
              .Text1(i).Left = i * 200
              .Text1(i).Visible = True
          Next i
      End With
  End Sub

3. Create a Sub Main procedure to be set as Startup object for the project by
  adding the following code to Module1:

  Sub Main()
  	MyTabSetup
  	Form1.Show
  End Sub

4. From the Project menu, select Project1 Properties, and on the General tab,
  select Sub Main as the Startup Object.

5. Run the application and there should be one TextBox on each tab.

6. The procedure can also be called before the Show method of the form when ever
  the form needs to be displayed. For example, if the form was closed and
  needed to be shown from the click event of a CommandButton, simply place the
  following code in the click event of the CommandButton:

  Private Sub Command1_Click()
  	MyTabSetup
  	Form1.Show
  End Sub

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

MORE INFORMATION
================

Steps to Reproduce Behavior 
---------------------------

1. Create a Standard EXE project. Form1 is created by default.

2. From the Project menu, select Components, select Microsoft Tabbed Dialog
  Control 6.0, and click OK.

3. Draw the tab control (SSTab1) on the default form (Form1).

4. Draw a TextBox (Text1) on Form1 and set the Index property of Text1 to 0 and
  set the Visible property to False.

5. Place the following code in the load event of Form1:

  Dim i as integer
  For i = 1 To 3
      SSTab1.Tab = i - 1
      Load Text1(i)
      Set Text1(i).Container = SSTab1
      Text1(i).Top = i * (SSTab1.TabHeight + 100)
      Text1(i).Left = i * 200
      Text1(i).Visible = True
  Next i

Run the program and note that all the TextBox controls appear on a single tab
instead of one on each tab.

Additional query words:

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Keywords          : kbTabCtrl kbVBp500bug kbVBp600bug kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600
Version           : WINDOWS:5.0,6.0
Issue type        : kbbug
Solution Type     : kbpending

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